Anti-Citrullinated Proteins Antibodies Promote Synovial Fibroblast Migration in Rheumatoid Arthritis

Meng Sun¹, Vijay Joshua¹, Aase Haj Hensvold¹, Sergiu-Bogdan Catrina², Lars Klareskog³, Vivianne Malmström⁴, Heidi Wähämaa¹ and Anca I Catrina¹, ¹Medicine, Rheumatology Unit, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden, ²Molecular Medicine and Surgery, Molecular Medicine and Surgery, Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden, ³Department of Medicine, Rheumatology Unit, Karolinska Institute, Stockholm, Sweden, ⁴Medicine, Rheumatology Unit, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden

Meeting: 2014 ACR/ARHP Annual Meeting

Keywords: ACPA, fibroblasts and rheumatoid arthritis (RA)

Session Information

Title: B cell Biology and Targets in Autoimmune Disease: Rheumatoid Arthritis and Related Diseases

Session Type: Abstract Submissions (ACR)

Background/Purpose

The presence of anti-citrullinated proteins antibodies (ACPAs) in RA is associated with aggressive disease phenotype and bone destruction. As synovial fibroblasts (SFs) are considered key players of both synovial inflammation and bone destruction in rheumatoid arthritis (RA), we studied the effect of ACPAs on fibroblasts migration.

Methods

Human dermal fibroblasts (HDFs) were obtained from PromoCell. SFs were isolated from synovial tissue of RA patients (RASFs) by enzymatic digestion. ACPA positive and negative IgGs were separated from plasma of RA patients and monoclonal anti-citrullinated antibodies were generated from RA synovial fluid by single B-cells¹. Migration scratch assays were performed using either RASFs or HDFs to test the effect of ACPAs, anti-citrullinated monoclonal antibodies and appropriate negative controls. The effect of a phosphatidyl inositol-3-kinase (PI3K) inhibitor (wortmannin) and a focal adhesion kinase (FAK) inhibitor (PF-573228) was tested. Light microscopy images were taken at baseline and after 6 hours incubation and analyzed using NIH ImageJ to calculate migration index. Cytotoxicity and proliferation assays were done in parallel with migration assays.

Results

ACPAs but not control IgGs induced a 3.9±0.5 (mean±SD) fold increase in HDFs and a 2.6±0.5 (mean±SD) fold increase in RASFs migration (p<0.05). PI3K but not FAK inhibition almost completely abolished ACPAs effects, with minimal fold migration increase of 1.4±0.4 (mean±SD). No difference in either cytotoxicity or proliferation rate were observed between different treatments. One out of three different anti-citrullinated monoclonal antibodies displayed similar mig

Conclusion

We describe a novel effect of ACPAs, providing a link between synovial fibroblasts and the adaptive immune system. We further suggest that different fine specificities of ACPAs might have distinct impact on disease pathogenesis.

1. Amara, K. et al. Monoclonal IgG antibodies generated from joint-derived B cells of RA patients have a strong bias toward citrullinated autoantigen recognition. J Exp Med 210, 445-55 (2013).

Disclosure:

M. Sun,
None;

V. Joshua,
None;

A. H. Hensvold,
None;

S. B. Catrina,
None;

L. Klareskog,
None;

V. Malmström,
None;

H. Wähämaa,
None;

A. I. Catrina,
None.

« Back to 2014 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/anti-citrullinated-proteins-antibodies-promote-synovial-fibroblast-migration-in-rheumatoid-arthritis/